ML19353A176

Final Significant Const Deficiency Repts 6 & 10 Re Emergency Diesel Generator Defective Shafts & Springs & Defective Emergency Diesel Generator Roller Pins,Initially Reported 780725 & 1103,respectively.Shafts Replaced & Pins Repaired

ML19353A176
Person / Time
Site:	Waterford
Issue date:	09/23/1980
From:	Aswell D LOUISIANA POWER & LIGHT CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, LPL-15163, NUDOCS 8101070384
Download: ML19353A176 (7)

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LPL 15163 Q-3-A35.07.06 Q-3-A35.07.10 Q-3-A35.02.01 Mr. K.

't. Seyfrit, Director, Region IV U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement 611 Ryan Placa Drive, Suite 1000 Arlington, Texas 76012 SU3 JECT: Waterford SES Unit No. 3 Docket No. 50-382 Final Report of Significant Construction Deficiencies No. 6 and No. 10 No. 6

" Emergency Diesel Generators - Defective Shaf ts & Springs" No. 10

" Defective Emergency Diesel Generator Roller Pins"

REFERENCE:

LP&L Letter, LPL 10343 dated December 29, 1978 LP&L Letter, LPL 10233 dated December 5, 1978 As arended by LPL 10316 dated December 19, 1978 As amended by LPL 11903 dated August 31, 1979 As amended by LPL 12319 dated October 31, 1979 LP&L Letter, LPL 13322 dated March 14, 1980

Dear Mr. Seyfrit:

In accordance with the requirements of 10CFR50.55(e), we are hereby providing two copies of the Final Report of Significant Construction Deficiency No. 6,

" Emergency Diesel Generators-Defective Shafts & dprings" and two copies of the Final Report of Significant Construction Deficiency No.10, "Def ective Emergency Diesel Generator Roller Pins."

If you have any questions, please advise.

Very truly yours, f\\)

M4 D. L. Aswell DLA/LL3/grf ec:

1)

Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.

20535 (with 15 copies of each report) 2)

Director Office of Management Information and Program Control U. S. Nuclear Regulatory Cc= mission Washington, D. C. 20555 (with 1 copy of report) 8101070 23II'f

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Final Report of Significant Construction Deficiency ':o. 6 Energe cv Diesel Generators-Defective Shafts i Springs J

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FINAL REPORT SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 6 EMERGENCY DIESEL GENERATORS-DEFECTIVE SHAFTS & SPRINGS l

INTRODUCTION I

This report is submitted pursuant to 10CFR50.55(e) (3).

It describes a deficiency in the emergency diesel generators supplied by Cooper-Bessemer Company for LP&L's Waterford Steam Electric Station Unit No. 3.

I DESCRIPTION i

i On July 25, 1978, Cooper-Bessemer Company pursuant to 10CFR21 notified the USNRC - Of fice of Inspection and Enforcement, Washington, D. C.,

of defective shafts and springs in the Emergency Diesel Generators supplied for LP&L's %'aterford SES Unit No. 3 at Taft, Louisiana.

A.

Shafts The defect exists in the two shaf ts which drive the engine speed control l

governor and the engine overspeed shutdown governor on each engine.

The splined driven end of the shafts was manufactured two inches icnger than required by des'.gn specification.

The additional length causes the shaft spline to misa'.ign with the splined drive bushing, resulting in marginal engagement of the splined surfaces.

This defect is considered to be reportable and is described in Attachment A (Cooper-Bessemer Co. letter to NRC dated July 25, 1978).

B.

Springs The defect exists in a spring which operates the overspeed shutdown 'outter-

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fly valve on the engine turbochanger air inlet connection.

The spring is plated with electrolytically deposited cadmium to prevent corrosion.

Several identical springs have recently failed on units still in the process of manu-

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l facture at C.E.S.

The cause of failure has been determined to be cracks in j

the base metal caused by the electrolytic plating process.

This defect is considered to be non-reportable and is described in Attachment 3 (Cooper

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Energy Services letter to NRC dated July 25, 1978).

i SAFETY IMPLICATIONS A.

Shafts l

I f the units were to fail during operations, the following consequences would result:

Overspeed Shutdown Governor shaf t failure, only - The unit would continue to operate normally, but would lose overspeed protection.

Speed Control C7vernor shaf t f ailure, only - The unit speed would rapidly proceed to overspeed, at which point the Overspeed Governor would effect a shutdown of the unit.

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l Simultaneous failure of both shafts - The unit speed would rapidly increase out af centrol until a mechanical failure occurred, placing the unit out of service.

3.

Springs If the units were operational and the spring were to f ail, one of the two overspeed protection devices provided on each engine would fail to perform.

However, the other overspeed protection device, a fuel shut-of f mechanism activated by a mechanically driven speed governor, would not be affected by the spring failure and would provide independently effective engine i

overspeed protection.

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CORRECTIVE ACTION l

Cooper Energy Services has f abricated new governor drive shaf ts, thus correct-ing the deficiency in the length of the shaft.

The defective spring has been remanufactured f rom a material that will not crack as a result of the electrolytic plating process.

Replacement of the new shafts and springs was accomplished by Gulf Engineering Company, Inc., under the supervision of a Cooper-Bessemer representative. The work was completed during the week ending September 19, 1980, and is docu-mented in Gulf Engineering Traveler Nos. P5-233 and P5-229.

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' Office of Inspecticn and Enforcement U. S. !!ucica r P.cgul a te ry Ccani s s i ca 1.Hashington, D. C.

20555 Attn:

Director of' Ins?ection cnd Enforce =ent;

' Gent.lonen :

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In ccordar.cc with'10CPP. Part 21, this letter uil! crovide

. notification of a def ect that has been cete:nined to exist in tuo crercency stand:y diesel-generator sets s:.:0;-l i e d to E ba s c 0

. Services, incorportted, ;iew York, ::. Y. for L uisiana Power

. sad Light C pany's "aterford

clear Station 63 at Taf t, Louisiana.

The defect exists in the two shafts which drive the engine speed contr:I governcr and the engine avers;'eed :hutdcan covernor on cach engine.

The splined criven end of thc shaf ts ues r:anv-factured t,;s inches lcnger th:n required by design specifica:icn.

length cause; thi. shaft spline to =isalian uith The dditional the splined drive busning, resuiting in carginal engagencct of the splined *.urfaces.

The diesel-genert:or units are not oper:tional at this ti=a, so there is r.c actu 1 safety hazard created by the defect.

If the units were operatic:.21 nd the shorts were to fail, follow-ing would t:e the consequences:

Overspeed Shutdcun Gevernor shaft failure, only - The unit would cer.:.inue to operate nor ally, but uccid lose overspeed protection.

Speed Control Governor shaf t failure, only - The unit speed would rapidiy prc: ecd to everspeed, et wnica point the Over peri l

Geyernor would cifect a shutdcr n o f the uni t.

t S 'r.:ul t: n e c u s f ailure of bo th shaf ts - The unit s:ced veuld rapidly increase out cf centrol until a =cchanical failurc occurred, placing the unit cut cf service.

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LOUISIANA POWER & LIGHT COMPANY WATERFORD SES UNIT No. 3 1

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I Final Report of j

Significant Construction Deficiency No. 10 I

Defective Emergency Diesel Generator Roller Pins g

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FINAL REPORT SIG';IFICANT CONSTNUCTION DEFICIENCY NO.10 DEFECTIVE EMERGENCY DIESEL CENERATOR ROLLER ut.

!NTRODUCTION This report is sub=itted pursuant to 10CFR50.55(e) (3).

It describes a deficiency in the emergency diesel generators supplied by Cooper Energy Services for Louisiana Power & Light Co=pany's Waterford Steam Electric Station Unit No. 3 and others.

DESCRIPTION On November 3, 1973, Cooper Energy Services pursuant to 10CFR21 notified the USNRC-Office of Inspection and Enforcement, Washington, D.C., of a defective roller pin in the crosshead subassembly of each power cylinder within a KSV Power Engine.

The extent of the deficiency is as follows:

Each power cylinder has one inlet and one exhaust push rod assembly and two valve crosshead assemblies.

The valve crosshead asse=bly contains a crosshead, a roller pin, and a pin collar. During a recent perfor=ance test on this engine at another facility, it was found that some subassemblies showed abnormal wear on the surface of the roller pin. No engine shutdown nor malfunction was experienced, but it is felt by the manufacturer that over a longer period of engine operation this abnormal wear could progress far enough to cause the engine to calfunc-tion.

This defect is considered to be reportable and is described in Attach-ment A (Cooper Energy Service letter to NRC dated November 3, 1978).

SAFETY IFJLICATIONS This deficiency, if left uncorrected, could possibly cause an engine malfunc-tion.

There would be no significant safety implication of engine calfunction during normal plant operation. However, this deficiency could invalidate some of the assumptions used in the safety analysis report.

If a design basis acci-dent (e.g., LOCA or main stean line break) were to occur coincidentally with a loss of of fsite power, and the diesel-generators did not perfor= in accordance with specifications, then some essential ecuipment used to mitigate the conse-quences of the postulated accident could be degraded.

CORRECTIVE ACTION The corrective action taken by Cooper Energy Service was to redesign the diameter of the rollsr pin to provide an interference fit at the assembly between the roller pin and the crosshead and reduce the clearance between the roller pin and the collar.

In addition, the hand flaring operation to seat the pin ends into chanfer on the crosshead has been replaced by a more consistent and posi-tive press operation.

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Corrective action work on the emergency diesel generators was acecmplished by Gulf Engineering Coe.pany, Inc.. under the supervision of a Cooper-Bessemer representative.

Corrective repairs consisted of replacement of the inlet and exhaust valve crosshead assemblies with those of the new design.

This work was completed during the week ending September 19, 1980, and is documented in Gulf Engi-i neering Traveler Nos. P5-233 and 13-229 I

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0 C3 COOPE3-GESSEMER COT.lP/:rJY 0

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Of'fice of Inspectior, and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.

20555 i

ATTH:

Director o'f Inspection a'nd Enforcement I

i, Gentlemen:

In.accordance with 10CFP. Part 21, this letter is notification of a deficiency found 9-13-78 within a KSV Power Engine supplied and manufactured by Cooper Energy Services.

This engine is part o f the emergency standby diesel-generator set supplied for installation at (4) four licensees' stations.

4 The extent of the deficiency is as follows:

Each power cylinder has (1) inlet and (1) exhaust push rod assembly and (2) valve crosshead assemblies Part No. Z25-1-2#10.

This sub-assembly contains; a crosshead Part No. JS-25-1G, a roller pin Part No. JS-25-lP, and a pin collar Part No. JS-25-lP..

During a on this engine, it was found that some recent performance test sub-assemblies showed abnormal wear on the surface of tne roller No engine shutdown nor mal-function has been experienced, pin but it is felt that over a longer period of. engine operation this abnormal wear could progress far enough to cause the engine to mal-function.

The corrective action taken by C.E.S.

is to redesign to increase (JS-25-lP) to provice an inter-the diameter of tae roller pin ference fit at assembly between the roller pin and the crosshead

.(JS-25-lG) and reduce the clearance between the roller pin and the collar (JS-25.1M).

In addition the hand flaring operation the pin ends into chamfer on the crosshead has been to seat replaced by a more consistent and positive press operation..The sub-assemblies in field units named below are to be inspected and replaced if required.

The time span for the execution of the.

change out by C.E.S. on fic'd units will be dependent upon avail-ability of units for rework but will be done as soon as is practi-cable.

The following engines which have had field. running at-the licensees' sites are to be inspected by C.E.S. to determine if cam rollers Cam have becor:e slucgish and incipient cam scuf fing is occurring.

or cam roller scuffing can.be an indication of a worn roller pin or collar.

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Attachment A - pg 2 of 2 g,

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en:ber 3,1970 Hebraska Public Powdr, Co o p e r S t a t i o n', S rf's 7102 & 7103.

Coranonweal t h Ed i s on, Zion 1 & 2, SN-7090, 7091, 7092, 7093

& 7094.

The following engines at the licensees' sites which have not iiad field running are to have the inlet and exhaust valve cross-head assemblies replaced with those of the new design.

Pennsylvania Power & Light, Susquehanna 1 & 2, SN's 7157, 7158, 7159 and 7160.

Louisiana Power & Light, Waterford 3, SN's 7170 & 7171.

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Bender Vice President & General Manager CB Reciprocating Products lil cc:

Ebasco Services, Inc.

Two Rector Street New York, N.Y.

10006 ATTN:

D. Sandiforth, Supervising Engr.

L. Spin' son, Site Quality Program Mgr.

P.O.

Box 70 8 Killona, Louisiana 70065.

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